At twenty, Sheng Luonuan is reborn with a stranger's heart, only to learn the truth at the Bridge of Helplessness: Leng Siye, who has waited for her through three lifetimes, is the heart donor. She rushes to the imperial capital, breaking into the world of the rumored 'heinous' Fourth Master Leng—a man trapped in darkness by childhood trauma and fearful of sunlight. The cafeteria changes hands, midnight spicy dishes are kept warm; he loves her deeply into his very bones with silence. She guides him out of the darkness with her body temperature, laughing as she demands a princess carry and kissing his trembling brows and eyes. Separated for a month, he promises his return over the phone; she waits quietly in the sunlight, waiting for one heart to find another. Across three lifetimes, this time it is her turn to run toward him in the darkness.